Kuklev Dmitry V, Smith William L
Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Chem Phys Lipids. 2006 Nov-Dec;144(2):172-7. doi: 10.1016/j.chemphyslip.2006.09.002. Epub 2006 Oct 11.
Three fatty acids were synthesized from commercially available alpha-linolenic, stearidonic and eicosapentaenoic acids by C2-elongation using a four step preparative technique. The parent fatty acid methyl esters were reduced to alcohols with LiAlH(4), converted to bromides by treatment with triphenylphosphine dibromide, coupled with a lithiated C2-elongation block--2,4,4-trimethyl-2-oxazoline--to form the corresponding 2,2-dimethyloxazolines of C2-elongated fatty acids, and finally, converted to the target polyunsaturated fatty acids by acidic alcoholysis. Yields of more than 60% were achieved on a gram scale. The resulting 11Z,14Z,17Z-eicosatrienoic, 8Z,11Z,14Z,17Z-eicosatetraenoic and 7Z,10Z,13Z,16Z,19Z-docosapentaenoic acids were obtained as colorless oils with >98% purity and could be used for biochemical investigations without additional purification. The elongated fatty acids were free of byproducts that could result from Z-E isomerization or migration of double bonds.
采用四步制备技术，通过C2-延伸反应，由市售的α-亚麻酸、十八碳四烯酸和二十碳五烯酸合成了三种脂肪酸。将母体脂肪酸甲酯用LiAlH(4)还原为醇，用三苯基膦二溴化物处理转化为溴化物，与锂化的C2-延伸砌块——2,4,4-三甲基-2-恶唑啉——偶联，形成C2-延伸脂肪酸的相应2,2-二甲基恶唑啉，最后通过酸性醇解转化为目标多不饱和脂肪酸。克级规模的产率超过60%。得到的11Z,14Z,17Z-二十碳三烯酸、8Z,11Z,14Z,17Z-二十碳四烯酸和7Z,10Z,13Z,16Z,19Z-二十二碳五烯酸为无色油状物，纯度>98%，无需进一步纯化即可用于生化研究。延伸后的脂肪酸没有因Z-E异构化或双键迁移而产生的副产物。
